<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      title="头条"
      left-arrow
      @click-left="$router.back()"
    />
    <!-- main-wrap -->
    <div class="main-wrap">
      <!-- 加载中模块 -->
      <div v-if="isLoading" class="loading-wrap">
        <van-loading color="#3296fa" vertical> 加载中... </van-loading>
      </div>
      <!-- 加载完成，文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>
          <!-- <van-button
            v-if="article.is_followed"
            class="follow-bth"
            round
            size="small"
            :loading="followLoading"
            @click="onFollow"
          >
            已关注
          </van-button>
          <van-button
            v-else
            class="follow-btn"
            type="info"
            round
            color="#3296fa"
            size="small"
            icon="plus"
            :loading="followLoading"
            @click="onFollow"
          >
            关注
          </van-button> -->
          <FollowIndex
            :articleId="article.aut_id"
            v-model="article.is_followed"
            @update-is_followed="article.is_followed = $event"
          />
        </van-cell>
        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          ref="article-content"
          v-html="article.content"
        ></div>
        <van-divider>正文结束</van-divider>
        <CommentList
          :commentList="commentList"
          :source="article.art_id"
          @onload-success="totalCommentCount = $event.total_count"
          @reply-click="onReplyClick"
        />
      </div>
      <!-- 加载失败 404 -->
      <div v-else-if="errStatus === 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除</p>
      </div>
      <!-- 加载失败 其他未知错误（如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败</p>
        <van-button @click="loadArticle" class="retry-btn">点击重试</van-button>
      </div>
      <!-- 底部区域 -->
      <div class="article-bottom">
        <van-button
          class="comment-btn"
          @click="isPostShow = true"
          type="default"
          round
          size="small"
        >
          写评论
        </van-button>
        <van-icon name="comment-o" color="#777" :info="totalCommentCount" />
        <van-icon name="star-o" color="#777" />
        <van-icon name="good-job-o" color="#777" />
        <van-icon name="share" color="#777" />
      </div>
      <!-- 发布评论弹层 -->
      <van-popup v-model="isPostShow" position="bottom">
        <CommentPost @post-success="onPostSuccess" :target="article.art_id" />
      </van-popup>
      <!-- 评论回复弹层 -->
      <van-popup v-model="isReplyShow" position="bottom" style="height: 80%">
        <CommentReply
          @update_reply_count="currentComment.reply_count = $event"
          @close="isReplyShow = false"
          v-if="isReplyShow"
          :comment="currentComment"
        />
      </van-popup>
    </div>
  </div>
</template>

<script>
import { getArticleById } from "@/api/article";
import { ImagePreview } from "vant";
import FollowIndex from "@/components/follow-user";
import CommentList from "./components/comment-list.vue";
import CommentPost from "./components/comment-post.vue";
import CommentReply from "./components/comment-reply.vue";

export default {
  name: "ArticleIndex",
  props: {
    articleId: {
      type: [String, Number, Object],
      required: true,
    },
  },
  data() {
    return {
      article: {},
      isLoading: true, // 加载状态
      errStatus: "", //请求异常状态
      totalCommentCount: 0, // 评论总数
      isPostShow: false, //发布评论弹层
      commentList: [], // 评论列表， 承接子组件的数据
      isReplyShow: false, // 回复弹层
      currentComment: {}, // 回复点击的对象
    };
  },
  provide() {
    return {
      articleId: this.articleId,
    };
  },
  components: {
    FollowIndex,
    CommentList,
    CommentPost,
    CommentReply,
  },
  created() {
    this.loadArticle(this.articleId);
  },
  methods: {
    previewImg() {
      const articleContent = this.$refs["article-content"];
      const allImg = articleContent.querySelectorAll("img");
      const images = [];
      allImg.forEach((item, index) => {
        images.push(item.src);
        item.onclick = () => {
          ImagePreview({
            images,
            startPosition: index,
          });
        };
      });
      // ImagePreview(allImg)
    },
    async loadArticle(articleId) {
      try {
        const { data } = await getArticleById(articleId);
        this.article = data.data;
        // 注意：数据更新后并不会同步更新页面，所以想要获取数据更新后的页面元素，需要延时处理
        setTimeout(() => {
          this.previewImg();
        }, 0);
      } catch (err) {
        if (err.response && err.response.status === 404) {
          this.errStatus = 404;
        }
        this.$toast.fail("获取数据失败");
      }
      // 加载完成
      this.isLoading = false;
    },
    onPostSuccess(data) {
      this.totalCommentCount++
      this.isPostShow = false;
      this.commentList.unshift(data.new_obj);
    },
    onReplyClick(comment) {
      this.currentComment = comment;
      this.isReplyShow = true;
    },
  },
};
</script>

<style lang="less" scoped>
@import "./github-markdown.css";
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>